The Ethiopian terrain makes land travel difficult. Because many areas are inaccessible by road and others are inadequately served by surface transportation, air transport is of great importance. A government-owned airline company, Ethiopian Airlines, handles both domestic and international air service. International airports serve Addis Ababa and Dire Dawa. The capital is connected by rail with the port of Djibouti, on an inlet of the Gulf of Aden. Ethiopia has 28,652 km (17,804 mi) of roads, of which 13 percent are paved. A highway links Addis Ababa with Nairobi, Kenya. The Voice of Ethiopia makes radio broadcasts daily in Amharic, Arabic, Somali, Afar, Oromifa, Tigrinya, English, and French.